I read this book cover to cover in one evening. It's such a fun read and introduced so many concepts. I enjoyed one of the chapters about Busy Beaver Problem so much that I spent a few days implementing Busy Beaver in several languages and wrote a program that visualizes how the Beaver travels on the tape: [...] This book is a must read for anyone interested in computers. This excellent book contains 66 short essays on the most important and interesting computing topics, such as compression, Turing machines, recursion, formal grammars, non-computable functions, neural networks and algorithms. The writing style of this book is casual and it contains almost no math. It's my favorite book of all time.
I've rated this book #1 in my Top 100 Programming, Computer and Science book list:
(If this link gets removed google for >>catonmat top 100 programming computer science books<< to find my article.)